It is well established that the prefrontal
cortex undergoes structural and also seemingly functional change with increasing age (see Grady, 2008 for review). Less established are effects on parietal cortex and Selleck Everolimus the right hemisphere white matter underlying these regions. However, it appears to be the case that older participants have significantly more activity in posterior parietal cortex whilst attending to an attentional cue (Jimura and Braver, 2010) and a general greater recruitment of these regions in other attention tasks (Grady, 2008). The authors propose that this age group is less efficient at utilizing attention, possibly as a result of loss of capacity (Jimura and Braver, 2010). Structurally, there is evidence of both cortical parietal atrophy (Bergfield et al., 2010) as well as age-related white matter hyperintensities in this region
(Murray et al., 2010). Results found here correspond well with these recent neuroimaging studies as we demonstrate the behavioural consequences of age related degeneration of attentional networks. The results outlined within this paper are important with respect to the groups studied here but beyond that the paradigm itself is a significant development. Our own previous research using a similar paradigm revealed that if task load is high enough even young healthy participants can miss items in the click here near periphery (Russell et al., 2004 see Lavie, 2005). Further adaptation of the basic method could be used to investigate attentional capacity across diverse groups such as those with left hemisphere damage or suffering from dementia, enabling the identification of the key brain regions and networks for integration of spatial and temporal components of attention. In conclusion, we have examined spatiotemporal attention processing capacity in two groups. The first (Experiment 1) consisted of patients with right hemisphere lesions, without neglect. Compared to next their healthily ageing counterparts,
these individuals suffer from a pathological loss of ability to discriminate simple stimuli even in the near periphery when they complete an unrelated task at screen centre. This loss is modulated by the amount of attention they must give the central task and temporally extends for a period of 850 msec. Secondly (Experiment 2), task modulations made it possible to examine the effects of healthy ageing on visual attention. Here we were able to show that an older group (mean age: 63 years) was as efficient as a much younger group when little attention was required at screen centre. However, they were greatly impaired across the visual field when they were required to allocate more attention centrally. They failed to discriminate simple letters and suffered from an AB of 450 msec.